Warming experiments underpredict plant phenological responses to climate change.

Warming experiments are increasingly relied on to estimate plant responses to global climate change. For experiments to provide meaningful predictions of future responses, they should reflect the empirical record of responses to temperature variability and recent warming, including advances in the timing of flowering and leafing. We compared phenology (the timing of recurring life history events) in observational studies and warming experiments spanning four continents and 1,634 plant species using a common measure of temperature sensitivity (change in days per degree Celsius). We show that warming experiments underpredict advances in the timing of flowering and leafing by 8.5-fold and 4.0-fold, respectively, compared with long-term observations. For species that were common to both study types, the experimental results did not match the observational data in sign or magnitude. The observational data also showed that species that flower earliest in the spring have the highest temperature sensitivities, but this trend was not reflected in the experimental data. These significant mismatches seem to be unrelated to the study length or to the degree of manipulated warming in experiments. The discrepancy between experiments and observations, however, could arise from complex interactions among multiple drivers in the observational data, or it could arise from remediable artefacts in the experiments that result in lower irradiance and drier soils, thus dampening the phenological responses to manipulated warming. Our results introduce uncertainty into ecosystem models that are informed solely by experiments and suggest that responses to climate change that are predicted using such models should be re-evaluated.

Are functional traits good predictors of demographic rates? Evidence from five neotropical forests.

A central goal of comparative plant ecology is to understand how functional traits vary among species and to what extent this variation has adaptive value. Here we evaluate relationships between four functional traits (seed volume, specific leaf area, wood density, and adult stature) and two demographic attributes (diameter growth and tree mortality) for large trees of 240 tree species from five Neotropical forests. We evaluate how these key functional traits are related to survival and growth and whether similar relationships between traits and demography hold across different tropical forests. There was a tendency for a trade-off between growth and survival across rain forest tree species. Wood density, seed volume, and adult stature were significant predictors of growth and/or mortality. Both growth and mortality rates declined with an increase in wood density. This is consistent with greater construction costs and greater resistance to stem damage for denser wood. Growth and mortality rates also declined as seed volume increased. This is consistent with an adaptive syndrome in which species tolerant of low resource availability (in this case shade-tolerant species) have large seeds to establish successfully and low inherent growth and mortality rates. Growth increased and mortality decreased with an increase in adult stature, because taller species have a greater access to light and longer life spans. Specific leaf area was, surprisingly, only modestly informative for the performance of large trees and had ambiguous relationships with growth and survival. Single traits accounted for 9-55% of the interspecific variation in growth and mortality rates at individual sites. Significant correlations with demographic rates tended to be similar across forests and for phylogenetically independent contrasts as well as for cross-species analyses that treated each species as an independent observation. In combination, the morphological traits explained 41% of the variation in growth rate and 54% of the variation in mortality rate, with wood density being the best predictor of growth and mortality. Relationships between functional traits and demographic rates were statistically similar across a wide range of Neotropical forests. The consistency of these results strongly suggests that tropical rain forest species face similar trade-offs in different sites and converge on similar sets of solutions.

Temporal variation in the pollen:ovule ratios of Clarkia (Onagraceae) taxa with contrasting mating systems: field populations.

Among plants, pairs of selfing vs. outcrossing sister taxa provide interesting systems in which to test predictions concerning the magnitude and direction of temporal changes in sex allocation. Although resource availability typically declines towards the end of the growing season for annual taxa, temporal changes in mating opportunities depend on mating system and should change less in selfing taxa. Consequently, given that the pollen:ovule (P:O) ratio of flowers reflects the investment in (and potential fitness pay-off due to) male vs. female function, we predicted that the P:O ratio should also be less variable among and within selfers than in closely related outcrossers. To test these predictions, we measured temporal changes in sex allocation in multiple field populations of two pairs of sister taxa in the annual flowering plant genus Clarkia (Onagraceae). In the outcrossing Clarkia unguiculata and the selfing Clarkia exilis, ovule production declined similarly from early to late buds, whereas pollen production remained constant or increased in the outcrosser but remained constant or decreased in the selfer. Consequently, the P:O ratio increased within unguiculata populations but marginally increased or stayed constant in exilis populations. In all populations of the selfing Clarkia xantiana spp. parviflora and the outcrossing C. x. spp. xantiana, both ovule and pollen production per flower declined over time. The effects of these declines on the P:O ratio, however, differed between subspecies. In each xantiana population, the mean P:O ratio did not differ between early and late flowers, although individuals varied greatly in the direction and magnitude of phenotypic change. By contrast, parviflora populations differed in the mean direction of temporal change in the P:O ratio. We found little evidence to support our initial predictions that the P:O ratio of the selfing taxa will consistently vary less than in outcrossing taxa.

Trade-offs between male and female reproduction associated with allozyme variation in phosphoglucoisomerase in an annual plant (Clarkia unguiculata: Onagraceae).

The genotype of an individual for allozymes such as phosphoglucoisomerase (Pgi) is often not neutral with regard to fitness. Studies of several taxa have found consistent fitness differences among Pgi genotypes expressing different allozymes. We conducted a greenhouse experiment with Clarkia unguiculata to determine whether allelic variation at the Pgi-C1 locus may affect components of male and female function. We found significant differences in siring success between pollen donors homozygous for different Pgi alleles. When a mixture of pollen was applied to stigmas under conditions of gametophytic competition (more pollen deposited on stigmas than there are ovules available to fertilize), donors homozygous for the C allele of Pgi sired more seeds per fruit than B-allele donors. Differences between genotypes with respect to female fertility per fruit contrasted with the male advantage associated with the C allele. Recipients homozygous for the C allele produced fruits with more aborted seeds and fewer viable seeds than recipients homozygous for the B allele. These results suggest that allelic variation at a single locus may have opposing effects on male and female reproductive success in C. unguiculata, and that trade-offs between the two types of reproductive success could contribute to the maintenance of variation at the Pgi-C1 locus.

Patient education model for increasing handwashing compliance.

BACKGROUND: A review of the literature on handwashing has documented the absence of research on the education of the patient as an intervention model for changing staff behavior regarding handwashing compliance. The primary objective of this project was to conduct a prospective control study of the effect of patient handwashing education on staff compliance with handwashing. METHOD: A prospective, controlled, 6-week intervention/control study was performed in 4 community hospitals in South Jersey. Each hospital served as its own control. Patients were educated within 24 hours of admission about the importance of asking their health care workers to wash their hands. Soap usage and handwashing was calculated by bed-days. Patient follow-up was conducted through telephone interviews 2 weeks after discharge. RESULTS: The patient handwashing education model increased soap usage by health care workers an average of 34% (P =.021); this increase was consistent across hospitals regardless of the initial soap usage rates. Of the patients interviewed, 81% read the materials provided, 57% asked health care workers whether they had washed their hands, and 81% of this 57% said they received positive responses. CONCLUSIONS: For the first time, our findings document that education of patients regarding their role in monitoring handwashing compliance among health care workers can increase soap usage and handwashing and provide sustainable reinforcement of handwashing principles for health care workers.

Unusual computed tomographic presentation of cerebral toxoplasmosis.

The computed tomographic appearance of three cases of cerebral toxoplasmosis is described. Two of the patients were children with Hodgkin disease and the third was an adult with systemic lupus erythematosus. All patients were severely immunosuppressed. Computed tomography showed single or multiple hypodense rounded areas with peripheral annular contrast enhancement, suggesting pyogenic cerebral abscesses. Pathologic correlation is presented. The importance of diagnosis and early treatment is emphasized.

Properties of a local anesthetic receptor in rat brain.

Saturable binding of local anesthetics in rat brain homogenates was demonstrated using (14C)-lidocaine and (3H)-bupivacaine. Saturation analyses revealed a single class of binding sites for lidocaine and bupivacaine. A series of drugs with local anesthetic properties inhibited this binding, while drugs without local anesthetic activity did not affect the specific binding. Specific binding of lidocaine and bupivacaine was maximal from pH 8 to 10; the pH versus binding profile was similar to that reported for local anesthetic blocking of peripheral nerve conduction. These characteristics suggest that binding of local anesthetics to this or similar sites mediates their pharmacological activity.

Simple and safe heparin regimen for acute ischaemia.

The risk/benefit ratio of acute anticoagulation in ischaemic cerebro-vascular disease is not clearly established. A simple and safe intermittent intravenous heparin regimen (20000 IU daily) was used prospectively in 50 patients of 57 +/- 14 (m +/- sd) years of age whose blood pressures ranged from normal to severe hypertension. Twenty-two patients had cardiogenic embolism and the remaining had recurrent severe transient ischaemic attacks of recent onset or progressive cerebral infarcts. Time of exposure to heparin was 6.4 +/- 4 (m +/- sd) days. Two patients had recurrences of cerebral thromboembolism and none had bleeding complications. This is a safe and efficient method of anticoagulation for patients with cerebral ischaemia when continuous infusion of heparin or close monitoring of clotting times are not used routinely.

[Lateralization of the epileptogenic area by magnetic resonance imaging in temporal lobe epilepsy]. / Lateralização da área epileptogênica através de ressonância magnética na epilepsia do lobo temporal.

We studied 5 patients with medically refractory temporal lobe epilepsy using special methods of MRI, in order to localize the epileptogenic area. Coronal sequences were obtained with 5 mm sections from the posterior margin of the brainstem to the base of the frontal lobe using: "Inversion recovery T1" (TR = 2500 msec, TE = 26 msec, T1 = 600 msec) to analyse loss of internal structure and atrophy of the hippocampus, and morphology of the temporal lobe; and Spin-echo T2w (TR = 250 msec, TE = 120 msec) looking for abnormal high intensity signal. In two cases with left focal EEG the MRI showed atrophy, loss of internal structure and abnormal high intensity signal in the hippocampus, and atrophy of the anterior temporal lobe, ipsilaterally. One case with independent bilateral foci at the EEG showed atrophy, loss of internal structure and abnormal high intensity signal in the right hippocampus. Other case with right focal EEG showed bilateral atrophy of the anterior temporal lobes. Another case was normal. We conclude that this methodology can facilitate the surgical indication in temporal lobe epilepsy.

[Neurofibromatosis and extensive intracranial arterial occlusive disease (moyamoya disease). Report of a case]. / Neurofibromatose e doença arterial oclusiva intracraniana extensa (doença de moya-moya). Registro de um caso.

A 33-year-old female with neurofibromatosis and intracranial vascular lesions of the Moya-Moya type is reported. Clinical and angiographic aspects of both syndromes are discussed with respect to earlier reports of this rare association, with the conclusion that it produces slow intellectual and motor deterioration in adolescents or young adults. There are no specific guidelines to therapy, and the prognosis is mixed, some patients ceasing to progress at least for a few years.

[Visual and volumetric analysis with magnetic resonance of hippocampus formations in a group of patients with clinical diagnosis of temporal lobe epilepsy]. / Análises visual e volumétrica por ressonância magnética das formações hipocampais em um grupo de pacientes com diagnóstico clínico de epilepsia do lobo temporal.

The purpose of this study is to test the sensitivity of the volumetric analysis compared to the visual analysis of the hippocampal formations of a group of 153 patients with clinical diagnosis of temporal lobe epilepsy and candidates to temporal lobectomy, evaluated by magnetic resonance (MR), using a 0.5 Tesla machine and inversion-recovery T1-weighted images and 5 mm coronal slices. There was agreement between the prospective visual analysis and another retrospective visual analysis carried out by two independent observers (C = 0.748 and C = 0.720). There was also agreement between the retrospective analysis of the two investigators (C = 0.733). There was genuine agreement (C = 0.788) between the results of the qualitative and quantitative analyses carried out prospectively. Volume measurements showed a nonsignificant tendency to lateralize more cases of clinically presumed hippocampal atrophy. Our results confirm the reliability of a qualitative visual analysis and indicate the utility of hippocampal volumetry as a supplementary, objective and quantitative measure of hippocampal sclerosis.

Clinical, radiological and cerebrospinal fluid presentation of neurocysticercosis: a prospective study.

The wide clinical spectrum of neurocysticercosis has led to many attempts at clinical, radiological, CSF and other classifications. Based on an objective review of the relevant literature and on a prospective study of 42 patients with active neurocysticercosis, a new classification is proposed, based on clinical, tomographic, magnetic resonance and CSF evidence of viability of cysts. The first step is to define whether the disease is active or not. Inactive disease may be parenchymal calcifications or hydrocephalus. Active disease may be intraparenchymal, extraparenchymal or mixed. Statistical analysis of 42 cases with active disease shows intraparenchymal disease to occur in younger patients, perhaps more frequently in females, and to have a better prognosis than extraparenchymal of mixed disease. The latter appears to have the worst prognosis. Therapeutic implications are that only active disease warrants etiological therapy. There remain doubts about the best therapy for some infrequent subtypes of extraparenchymal and mixed disease.

The joint evolution of mating system, floral traits and life history in Clarkia (Onagraceae): genetic constraints vs. independent evolution.

Genetic correlations caused by pleiotropy or linkage disequilibrium may influence the joint evolution of multiple traits as populations or taxa diverge. The evolutionary transition from outcrossing to selfing has occurred numerous times and is often accompanied by phenotypic and genetic changes in multiple traits such as flower size, pollen-ovule ratio, stigma and anther maturity and the age of reproductive maturity. Determining whether the recurring patterns of multitrait change are because of selection on each trait independently and/or the result of genetic correlations among traits can shed light on the mechanism that accounts for such convergence. Here, we evaluate whether floral traits are genetically correlated with each other and/or with whole-plant traits within- and between-populations and taxa. We report results from a greenhouse study conducted on two pairs of sister taxa with contrasting mating systems: the autogamously selfing Clarkia exilis and its predominantly outcrossing progenitor C. unguiculata and the autogamous Clarkia xantiana ssp. parviflora and its outcrossing progenitor C. xantiana ssp. xantiana. We examined variation within and covariation among maternal families in three populations of each taxon with respect to the age at first flower, the rate of successive flower production and the number of days between bud break and anther dehiscence and stigma receptivity within individual flowers. Based on phenotypic divergence between sister taxa, bivariate regressions, correlations among maternal family means and analysis of covariance (ancova), we did not find unilateral support indicating that genetic constraints govern the joint distribution of floral and whole-plant traits.

The absence of cryptic self-incompatibility in Clarkia unguiculata (Onagraceae).

Many species exhibit reduced siring success of self-relative to outcross-pollen donors. This can be attributed either to postfertilization abortion of selfed ovules or to cryptic self-incompatibility (CSI). CSI is a form of self-incompatibility whereby the advantage to outcross pollen is expressed only following pollinations where there is gametophytic competition between self and outcross pollen. Under the definition of CSI, this differential success is due to the superior prefertilization performance (pollen germination rate and pollen tube growth rate) of outcross pollen relative to self pollen. Although CSI has been demonstrated in several plant species, no studies have assessed among-population variation in the expression of CSI. We conducted a greenhouse study on Clarkia unguiculata (an annual species with a mixed-mating system) to detect CSI, and we compare our observations to previous reports of CSI in C. gracilis and another population of C. unguiculata. In contrast to these previous studies of CSI in Clarkia, we used genetic rather than phenotypic markers to measure the relative performance of selfed vs. outcross pollen. In this study, we measured the intensity of CSI in C. unguiculata from a large population in southern California and we determined whether the magnitude of pollen competition (manipulated by controlling the number of pollen grains deposited on a stigma) influenced the outcome of competition between self and outcross pollen. In contrast to previous investigations of Clarkia, we found no evidence for CSI. The mean number of seeds sired per fruit did not differ between self and outcross pollen following either single-donor or mixed pollinations. In addition, the relative success of selfed vs. outcross pollen was independent of the magnitude of pollen competition. These results suggest that: (1) one of the few nonheterostylous species previously thought to be cryptically self-incompatible is completely self-compatible (at least in the population studied here) or (2) phenotypic markers may be problematic for the detection of CSI.

Size-dependent sex allocation within flowers of the annual herb Clarkia unguiculata (Onagraceae): ontogenetic and among-plant variation.

The relative allocation of resources to male and female functions may vary among flowers within and among individual plants for many reasons. Several theoretical models of sex allocation in plants predict a positive correlation between the resource status of a flower or individual and the proportion of reproductive resources allocated to female function. These models assume that, independent of resource status, a negative correlation exists between male and female investment. Focusing on the allocation of resources within flowers, we tested these theoretical predictions and this assumption using the annual Clarkia unguiculata (Onagraceae). We also sought preliminary evidence for a genetic component to these relationships. From 116 greenhouse-cultivated plants representing 30 field-collected maternal families, multiple flowers and fruits per plant were sampled for gamete production, pollen : ovule ratio, seed number, ovule abortion, seed biomass/fruit, mean individual seed mass, and petal area. If sex allocation changes as predicted, then (1) assuming that flowers produced early have access to more resources than those produced later, basal flowers should exhibit a higher absolute and proportional investment in female function than distal flowers and (2) plants of high resource status (large plants) should produce flowers with a higher proportional investment in female function than those of low resource status. Within plants, variation in floral traits conformed to the first prediction. Among plants and families, no significant effects of plant size (dry stem biomass) on intrafloral proportional sex allocation were observed. We detected no evidence for a negative genetic correlation between male and female investment per flower, even when controlling for plant size.

Laboratory evaluations of the thermal degradation properties of toxic organic materials in sewage sludge.

Laboratory thermal decomposition studies were performed to evaluate potential emissions from sewage sludge incinerators. Precisely controlled thermal decomposition experiments were conducted on sludge spiked with mixtures of hazardous organic compounds, on mixtures of pure compounds without sludge, and on unspiked sludge. Experiments were conducted in nitrogen and air atmospheres with gas phase reaction times of 2.0 seconds over the temperature range 300 degrees C-1000 degrees C. It was found that sludge inhibited the decomposition of moderately stable spiked contaminants but accelerated the decomposition of the most stable components. This effect was attributed to radical scavengers produced by the sludge matrix at lower temperatures which then decomposed at higher temperatures. A multiple hearth simulation study suggested that most of the organic material present in the sludge matrix is vaporized within the upper hearths that are held at lower temperatures and may consequently escape from such incinerators undestroyed. A number of stable byproducts resulted from the sludge decomposition that may be of environmental concern.

High-dose praziquantel for neurocysticercosis: efficacy and tolerability.

Standard therapeutic regimens of praziquantel for neurocysticercosis use daily doses of 50 mg/kg for 15-21 days, with prolonged remission being achieved in 60-80% patients. In this prospective study, 100 mg/kg daily was used for 10 days in 13 patients aged 32 +/- 15 years (mean +/- SD) with severe intra-, extra-parenchymal or mixed forms of neurocysticercosis. Patients were monitored with computerized tomography and cerebrospinal fluid (CSF) examination on days 1, 5 and 10. Full blood count, sedimentation rate, blood sugar, urea, creatinine, bilirubin, liver transaminases, alkaline phosphatase, urine analysis and electrocardiogram were carried out before and after treatment. Doses of dexamethasone and of other drugs used concomitantly were controlled. There was no toxicity, clinical or detected by the methods employed in the study. After 22 +/- 5 (mean +/- SD) months follow-up, 6 patients needed ventriculoperitoneal shunting, 2 had died, 7 were improved and led useful lives and 4 were in prolonged remission. There was no correlation between serum or CSF praziquantel correlation and outcome of treatment. The proposed regimen is well tolerated, may be as efficient as previously advocated regimens, requires less hospitalization time and may be adopted routinely for therapy of neurocysticercosis.

The computed tomographic spectrum of cerebral cysticercosis.

The main findings observed in computed tomography (CT) of the brain of 116 patients with cerebral cysticercosis are reviewed. Calcifications, cysts, nodules, hydrocephalus and inflammatory reactions are better detected by CT than through the use of any of the conventional neuroradiologic procedures, and surgical cases are more properly selected.